a. Field of the Invention
The present invention relates to material separation, and in particular, to an improved means and method of material separation such as coal cleaning or ore separation and processing.
b. Problems in the Art
The process of coal cleaning is a well known art. It is a continual goal to increase the efficiency of coal cleaning, which will in turn result both in better combustible coal and in savings in cost and time for the coal cleaning process. Increased efficiency and better monitoring is a goal of any type of material separation process.
In coal separation processes, the desired size or sorting of coal is selectable. The separation equipment, such as gravity separators, cyclones, shaker tables, etc., need to be adjusted and constantly monitored to make sure that the separation process is achieving the desired output of coal.
If the separation is not correctly proceeding, or if it is not being done efficiently, costs are incurred in utilizing coal that has been improperly cleaned, or in recleaning the coal.
If incorrect separation is detected, adjustments must be made to the separation equipment. An elementary method for monitoring the separation process is to visually examine samples of the cleaning output, and determine if the separation process is proceeding correctly. However, such requires direct and time-consuming manual labor and can result in significant amounts of improperly cleaned coal before adjustments can be made. Analogous problems exist with other types of material separation.
There is therefore a need for improved, less labor-intensive and more contemporaneous monitoring of material separation. Attempts have been made at solving this problem.
One recent approach with respect to coal cleaning has been to prepare synthetic particles of generally uniform size and density. The particles are color-coded or magnetically loaded plastic particles which are mixed into the coal being cleaned.
Because the synthesized particles are of known size and density, their ultimate destination in the separation process is predictable. They are therefore counted or otherwise detected at the output of the separation or cleaning process. By doing so, it can be determined whether the separation apparatus is functioning properly.
While this has represented an improvement in monitoring the efficiency of coal cleaning processes, there is still room for improvement. First of all, the synthetic particles simply do not sufficiently approach the actual characteristics of the coal being separated. There is therefore a considerable margin of error because the synthetic control particles behave significantly differently from actual coal particles in the separation and cleaning process. The synthetic particles cannot sufficiently simulate actual coal particles.
Secondly, the technology regarding the cleaning of coal has advanced to the point where increasingly smaller and smaller coal sizes are required to attain the desired levels of ash and sulfur removal. For example, today some advanced coal cleaning technologies require the density separation of sizes of coal on the order of minus 200 mesh. New cleaning units, such as true heavy-liquid cyclones, are being developed to clean these fine coals.
It is presently impossible to synthesize control particles on this size and density level. Thus, a very real need in the art exists for a method to monitor coal cleaning at this particle size level.
Attempts are being made to solve these problems by selectively tagging fine coal mineral fractions with ultrafine magnetite. While this may be applicable to very small particle sizes of coal, problems still exist with this method. First of all, very costly preparation techniques are needed to produce the control particles tagged with the ultrafine magnetite. Secondly, true chemical bonding of the magnetite particles with the coal particle surface cannot be made. Thus, the magnetite can become displaced as a result of abrasion or solvation in separation equipment, which will degrade the validity of the method. Third, this method cannot be effectively used for dense-media processes which themselves employ magnetite. These methods represent a large proportion of all current physical cleaning processes for coals. Fourth, detection of the particles would have to be by magnetic means. Because of the inherent makeup of coal cleaning processes, there would likely be interference and error because of the presence of residual magnetic media, as well as other complications.
Again, similar or analogous problems and deficiencies exist with respect to other types of material separation processes.
It is therefore a principal object of the present invention to provide a means and method for improved material separation which overcomes or solves the problems and deficiencies in the art.
A further object of the present invention is to provide a means and method as above described which can be utilized for all, or at least most, types of material separation processes, and for all, or at least many, types of materials.
A further object of the present invention is to provide a means and method as above described which can greatly increase the efficiency of material separation processes.
A further object of the present invention is to provide a means and method as above described which introduces control particles to assist in monitoring material separation efficiency, where the control particles react exactly the same to the material separation process as the material itself.
A still further object of the present invention is to provide a means and method a above described which is applicable to material separation of all sizes of material, including down to extremely small particle sizes at or smaller than minus 200 mesh.
Another object of the present invention is to provide a means and method as above described which produces control particles economically and efficiently, and gives results economically and efficiently.
A further object of the present invention is to provide a means and method as above described which is non-complex, readily usable, and presents a low margin of error.
A still further object of the present invention is to provide a means and method as above described which greatly enhances the ability to efficiently monitor material separation efficiency
These and other objects, features, and advantages of the present invention will become more apparent with reference to the accompanying specification and claims.